The physics-based TIE-GCM OTHITACS


Kodikara, Timothy

TIE-GCM (thermosphere-ionosphere-electrodynamics general circulation model) is a three-dimensional, time-dependent, physics-based model of the thermosphere and ionosphere ( The website hosts the open-source TIE-GCM code. TIE-GCM assumes hydrostatic equilibrium, constant gravity, steady-state ion and electron energy equations, and incompressibility on a constant pressure surface.

In this experiment, we use TIE-GCM version 2.0 (released on 21 March 2016) with a horizontal resolution of 2.5 by 2.5 in geographic latitude and longitude, and a vertical resolution of 0.25 scale-height. We specify the solar irradiance input to the model via an empirical solar proxy model—the extreme ultraviolet flux model for aeronomic calculations (EUVAC;; This empirical formulation uses the average of the daily solar flux F10.7 and its 81-day centred mean. Here, we use the value observed by the ground-based solar radio telescope, as it is more suitable for upper-atmospheric applications than the F10.7 adjusted for Earth-Sun distance. We use the Kp index-based ion convection model of Heelis et al. (1982; and the auroral particle precipitation scheme of Roble and Ridley (1987; with modifications of Emery et al. (2012; to specify the magnetospheric forcing, which describes the high-latitude mean energy, energy flux and electric potential. To account for the tidal forcing from the lower atmosphere, we use the global scale wave model (GSWM) of Hagan et al. (2001; to perturb the lower boundary of the TIE-GCM. Here, the GSWM specifies the migrating diurnal and semidiurnal and the nonmigrating diurnal and semidiurnal tides, which add perturbations to the zonal mean neutral temperature and horizontal winds, among others. We also add perturbations to the advective and diffusive transport via the constant eddy diffusion coefficient described in Qian et al. (2009;

Through this experiment, we provide access to the following diagnostic quantities at a cadence of 10 minutes:
Neutral temperature,
Neutral zonal wind,
Neutral meridional wind,
Neutral vertical wind,
Molecular oxygen,
Atomic oxygen,
Molecular nitrogen,
Nitric oxide,
Total neutral mass density,
TEC: total electron content,
Electron density,
Electron temperature,
Ion temperature,
O+ ion,
O2+ ion,
Electric potential,
Joule heating,
BX/BMAG: normalized eastward component of magnetic field,
BY/BMAG: normalized northward component of magnetic field,
BZ/BMAG: normalized upward component of magnetic field,
BMAG: magnetic field magnitude,
Zonal ExB velocity,
Meridional ExB velocity,
Vertical ExB velocity,
Zonal component of electric field,
Meridional component of electric field,
Vertical component of electric field,
Magnetic eastward component of electric field,
Magnetic downward (equatorward) component of electric field,
Geopotential height,
Geometric height ZG,
Pedersen conductivity,
Hall conductivity,
Pedersen ion drag coefficient,
Hall ion drag coefficient,
Aurora energy flux,
Aurora number flux.
OTHITACS (The open time-series of the high-resolution ionosphere-thermosphere aeronomic climate simulation)
Dr. Timothy Kodikara (
Spatial Coverage
Longitude -180 to 180 Latitude -88.75 to 88.75 Altitude: -7 level to 7 level
Temporal Coverage
2000-01-01 to 2023-12-31 (standard)
Use constraints
Creative Commons Attribution 4.0 International (CC BY 4.0) (
Data Catalog
World Data Center for Climate
86.16 TiB (94729668779584 Byte)
will be continued
Creation Date
Future Review Date
Cite as
Kodikara, Timothy (2023). The open time-series of the high-resolution ionosphere-thermosphere aeronomic climate simulation (OTHITACS). World Data Center for Climate (WDCC) at DKRZ.

The TIE-GCM is a well-established, self-consistent, physics-based model.
Model documentation:

TIE-GCM version 2.0 benchmark results:
The netcdf files store the model variables on a global grid with a time resolution of 10 minutes. The spatial resolution is 2.5 by 2.5 degrees latitude and longitude and 0.25 scale-height in the vertical, which is approximately 97 to 500 km altitude. The netcdf files provide full attributes describing units, dimensions, missing values and data type for each model variable.
Findable: 6 of 7 level;
Accessible: 2 of 3 level;
Interoperable: 3 of 4 level;
Reusable: 5 of 10 level
F-UJI online v2.2.5 automated
Method Description
Checks performed by WDCC. Metrics documentation: Metric Version: metrics_v0.5
Method Url
Result Date
Result Date
1. Number of data sets is correct and > 0: passed;
2. Size of every data set is > 0: passed;
3. The data sets and corresponding metadata are accessible: passed;
4. The data sizes are controlled and correct: passed;
5. The spatial-temporal coverage description (metadata) is consistent to the data, time steps are correct and the time coordinate is continuous: passed;
6. The format is correct: passed;
7. Variable description and data are consistent: spot checks passed
WDCC-TQA checklist
Method Description
Checks performed by WDCC. The list of TQA metrics are documented in the 'WDCC User Guide for Data Publication' Chapter 8.1.1
Method Url
Result Date
Contact typePersonORCIDOrganization

Is compiled by

[1] DOI Richmond, A. D.; Ridley, E. C.; Roble, R. G. (1992). A thermosphere/ionosphere general circulation model with coupled electrodynamics. doi:10.1029/92gl00401
[2] DOI Qian, Liying; Burns, Alan G.; Emery, Barbara A.; Foster, Benjamin; Lu, Gang; Maute, Astrid; Richmond, Arthur D.; Roble, Raymond G.; Solomon, Stanley C.; Wang, Wenbin. (2014). The NCAR TIE-GCM. doi:10.1002/9781118704417.ch7

Is supplemented by

[1] DOI Richards, P. G.; Fennelly, J. A.; Torr, D. G. (1994). EUVAC: A solar EUV Flux Model for aeronomic calculations. doi:10.1029/94ja00518
[2] DOI Solomon, Stanley C. (2005). Solar extreme-ultraviolet irradiance for general circulation models. doi:10.1029/2005ja011160
[3] DOI Heelis, R. A.; Lowell, J. K.; Spiro, R. W. (1982). A model of the high-latitude ionospheric convection pattern. doi:10.1029/ja087ia08p06339
[4] Roble, R. G.; Ridley, E. C. (1987). An auroral model for the NCAR thermospheric general circulation model (TGCM).
[5] DOI Emery, B. A.; Roble, R. G.; Ridley, E. C.; Richmond, A. D.; Knipp, D. J.; Crowley, G.; Maeda, S. (2012). Parameterization of the ion convection and the auroral oval in the NCAR Thermospheric General Circulation Models (No. NCAR/TN-491+STR). doi:10.5065/D6N29TXZ
[6] DOI Hagan, M. E.; Roble, R. G.; Hackney, J. (2001). Migrating thermospheric tides. doi:10.1029/2000ja000344
[7] DOI Qian, Liying; Solomon, Stanley C.; Kane, Timothy J. (2009). Seasonal variation of thermospheric density and composition. doi:10.1029/2008ja013643

Attached Datasets ( 24 )

Details for selected entry
[Entry acronym: OTHITACS_tiegcm] [Entry id: 3970937]